With 3,000 bikes on display, the world's largest bicycle museum includes some famous rarities.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

Found art has transformed this Pittsburgh neighborhood into a psychedelic dream.

Mysterious rocks that ring musically when struck.

A one-of-a-kind collection of a unique medium.

The famed architect designed this Minnesota gas station of the future with a lookout tower.

Homemade rockets, dinosaurs, and robots make this New York small business much more than a furniture store.

One man's swirling six-acre monument of stone.

The "Seinfeld" diner.

A bit of retro transportation flair preserved in the world's largest department store.

An artist's cute bronze subway sculptures belie his violent artistic past.

Three-story slide through the New Museum.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

The last of Philadelphia's wood-paved streets is now a landmark of terrible engineering.